Manufacture of artificial silk



Oct. 26, 1937. a. J. MEERDINK MANUFACTURE OF ARTIFICIAL SILK Filed Jan. 21,, 1936 I Patented Oct. 26, 1937 UNITED STATES PATENT OFFICE 2,097,084 MANUFACTURE OF ARTIFICIAL SILK Gerhard Jan Meerdink, Arnhem, Netherlands, as-

signor to American Enka Corporation, Enka, N. 0., a corporation of Delaware Application January 21, 1938, Serial No. 80,112

In Germany January 30,1935

Claims. (cue-s) w manufacture artificial silk threads having a roughened exterior simulating wool. Such attempts comprised generallya method whereby the 1,9 finished thread, i. e., thread having been spun,

' washed and dried, was passed over a thread guide having sharpened edges which were arranged in a manner intended to perform the function-of nicking thejdried thread in order to impart a ll roughened wool-like characteristic thereto. Such method, however, was not satisfactory owing to' the fact that the sharpened edges instead of merely picking the dry thread as desired often cut entirely through the relatively non-flexible go filaments which comprised the thread. A further disadvantage was encountered due to the fact that even when the filaments were not entirely out through, the portions nicked in the dry thread did not properly curl. 25 It is therefore an object of the present invene tion to provide an improved apparatus for rough-'- A ening artificial silk thread in order to impart thereto a wool-like appearance.

My invention more specifically contemplates a no method which includes the subjecting of artificial silk thread to a roughening action during its path of travel to'a collecting deviceimmediately after it has been extruded from the spinneret, and

passed through a coagulating bath. Another obas ject of my invention is the provision, in the ordinary combination of elements essential to the manufacture of artificial silk, of a thread guide or spinning funnel having abrasive material imbedded therein at points which contact directly so with the thread passing thereover or therethrough, respectively.

Other objects and advantages will be apparent from the following detailed description when considered in connection with the accompanying 45 drawing wherein:

Figure 1 designates a side elevation of the normal spinning pot, with a portion thereof broken away to show the improved spinning funnel; and 50 Figure 2 is an enlarged detailed sectional view .of the lower portion of the spinning funnel.

Whereas the following detailed description exemplifies the novel process and apparatus applied to the so-called "centrifugal spinning method", it;

ss is to be understood that practical results may be obtained by utilinng a roughened thread guide in association with a bobbin spinning process wherein the thread is collected on a rotatin holder.

Hitherto it has been deemed-impractical to 5 I attempt to roughen the exterior portions of a freshly spun thread in view of the known characteristics of such a thread which include principally the extreme sensitiveness of the same. However, the unobvious results which are now attained render my invention fundamentally novel.

In referring to the drawings, a is utilized to designate an artificial silk thread which has been extruded and led in a suitable manner into the .spinning pot or bucket b, by way of the spinning g funnel c. The lowermost portion of the spinning funnel-is roughened at d, as is more clearly "shown [in Figure 2. The formation of the roughened'surface 1! may be accomplished in various ways, one of whlch involves the fusing of the material of the funneladlacent to the surface near its outlet with an abrasive material, for example carborundum powder. The glass may be heated .sumciently and sprinkled with the said powder. which upon cooling may be cluned of non-adhering particles. is a It can readily be understood by those skilled in the art that when the thread is fed through the. spinning funnel into the rapidly rotating spinning pot, the centrifugal force set up within the pot causes the thread to be thrown against the walls thereof and by virtue of such action the thread is maintained continuously substantially at right angles to the spinning funnel. As the thread passes the outlet of the spinning funnel it rubs against the surface of the outlet which, owing to its roughened condition, imparts a pre-' determined amount'of' fric ion thereto;

A specific example which has been found to give excellent results consists in utilizing a spino ning funnel, the upper portion of which has an inside diameter of 13 mm. while the diameter of the lower portion is 8 mm. and the outlet is covered with No, 80 powderedv carborundum to a height of approximately 2 mm. within the in- I terior. of. the spinning funnel. The specifications given in the foregoing example are merely by way'of illustration and may be varied within reason without departing from the scope of the invention. The degree of roughening desired may 5 be determined by first measuring the resistance and ,sensitiveness of the particular freshly .spun thread which is to be roughened.

A further improvement in conducting the process exemplified in the accompanyin drawing is the employment of a pipe e (see Figure 1) through which a cooling fiuid such as water 'is supplied. This tends to lubricate the abrading surface thereby lessening the danger of injury to the individual filaments and enhancing the tendency of the tuftings broken away from funnel having a roughened thread contacting surface immediately adjacent its outlet end.

3. A process for producing artificial silk threads of wool-like character according to the wet spinning method which comprises extruding a cellulosic solution to form a plurality of parallel wet filaments which collectively make up a thread, leading the freshly spun wet filamentary thread to a spinning pot, twisting and collecting the same by the centrifugal action developed by the rotation of said pot and nicking the filaments at the surface of the thread during its passage through a spinning funnel guide by passing the same in frictional'contact with an abrasive surface.

4. An apparatus for manufacturing wool-like artificial silk threads from cellulosic solutions comprising in combination a centrifugal spinning pot, a thread guide funnel located above the pot and adapted for guiding thread thereinto-and means for roughenlng the surface of the thread as it passes through the thread guide funnel and before it is collected in said pot.

5. An apparatus for manufacturing wool-like artificial silk threads from cellulosic solutions comprising in combination a centrifugal spin- 

